Writing talk abstracts and outlines, newer speakers forget all the time that a talk is COMMUNICATION, and has an audience. You're speaking TO someone, and you should have an idea who that someone is before you write the talk, let alone deliver it.
If you don't know who your audience is, it's going to be a bad talk no matter how cool your tech is.
This (sadly) doesn't apply to academic conferences, where your audience is the paper review committee.